1. Field of the Invention
The present invention relates to a novel sulfonate useful as an organic peracid precursor for domestic bleach compositions such as a bleach composition for mold stains, a bleach composition for the kitchen and a bleach composition for clothes, and a process for producing the sulfonate. Further, the present invention relates to an oxygen bleach composition free from an irritative smell and having high bleaching power and persistence of bleaching power.
2. Description of the Related Art
Blackish stains on the ceiling, joints between the tiles and plastic wall in a bathroom, garbage strains at the corner of a sink, etc., are caused by a pigment produced by fungi of the genus Cladosporium and the like. Since such blackish stains cannot be removed with only a cleanser or a surfactant, a bleach composition comprising a chlorine bleaching agent such as a hypochlorite which is used in the form of a spray, are now on the market as a product for removing blackish stains.
Although bleach compositions comprising a hypochlorite are excellent in bleaching power, they are very harmful to the eyes and skin and, in particular, those to be used in the form of a spray are unsuitable for removing blackish stains on ceilings, etc. Further, consumers are reluctant to use a bleach composition comprising a hypochlorite in a small bathroom and the like, since it has a strong smell peculiar to a chlorine bleaching agent.
Furthermore, there is a problem that when a bleach composition comprising a hypochlorite is used in combination with an acidic detergent by mistake, a poisonous gas will be formed.
Recently, investigations have been made with respect to oxygen bleach compositions free from such dangers, e.g., a bleach composition comprising hydrogen peroxide or sodium percarbonate, a bleach activator and a peroxydisulfate.
In oxygen bleach compositions, use is usually made of a bleach activator together with a bleaching agent. Examples of the bleach activators include tetraacetylethylenediamine, tetraacetylglycoluril and pentaerythritol tetraacetate. However, such bleach activators have a strong irritative smell, since they form peracetic acid as an active bleach species, and they pose problems when they are practically used.
U.S. Pat. Nos. 4,684,551 (patented on Jan. 6, 1987; assignee: Procter & Gamble Co.), U.S. Pat. No. 4,859,800 (patented on Aug. 22, 1989; assignee: Clorox Co. & Zielske A.G.), 4,956,117 (patented on Sep. 11, 1990; assignee: Clorox Co. & Zielske A.G.) and 5,049,305 (patented on Sep. 17, 1991; assignee: Clorox Co. & Zielske A.G.) disclose compounds represented by the following general formula (a) as organic peracid precursors usable for the bleach compositions: ##STR2## wherein R.sup.6 represents a group represented by the formula: ##STR3## (wherein R.sup.7 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a group represented by the formula: ##STR4## (wherein R.sup.8 represents an alkyl, aryl or alkanol group having 1 to about 14 carbon atoms, R.sup.9 represents a hydrogen atom or an alkyl, aryl or alkanol group having 1 to about 10 carbon atoms, and R.sup.10 represents an alkylene, arylene or alkanolene group having 1 to about 14 carbon atoms). The alkanol group is a monovalent group derived from an alkanol represented by the formula: R--Ar--SO.sub.3 M (wherein R represents an alkyl group, Ar represents a divalent aromatic group and M represents an aklali metal or hydrogen atom), and the alkanolene group is a divalent group represented by the formula: ##STR5## (wherein R represents an alkyl group, and Ar represents a trivalent aromatic group).
However, when the compound represented by the above general formula (a) is used as an organic peracid precursor for achieving a further improved bleaching power in a system containing hydrogen peroxide, etc. and the organic peroxide precursor in high concentrations, an organic peracid formed by the perhydrolysis of the organic peracid precursor is consumed for the oxidation of sodium phenolsulfonate as the leaving group. Therefore, the intended effect cannot be obtained when a bleach composition comprising the compound represented by the above general formula (a) as an organic peracid precursor is used. In addition, the synthesis of the compound represented by the above general formula (a) includes a step of esterification of an acid with an alcohol through dehydration. However, this step is difficult to practice, which causes a problem in the sysnthesis of the compound on an industrial scale.
A literature other than the above patents also discloses the use of a compound of which leaving group is a phenol derivative as the organic peracid precursor. However, the expected effect cannot be obtained when such an organic peracid precursor is used for the same reasons as those in the above-described case wherein an organic peracid precursor, of which leaving group is sodium phenolsulfonate, is used.
Although an organic peracid precursor, of which leaving group is glucose, is also known, the substance which is prepared by an industrially possible esterification reaction of an acid with glucose, had poor physical properties as a solid and was severely colored. Namely, a substance as an organic peracid precursor intended by the inventors could not be obtained from an acid and glucose.
Under these circumstances, an object of the present invention is to provide an organic peracid precursor which does not give out an unpleasant irritative smell under bleaching conditions and which can be easily synthesized on an industrial scale from inexpensive starting materials, and a process for producing it. Another object of the present invention is to provide an oxygen bleach composition being free from the irritative smell and having high bleaching power and persistance of bleaching power.